August 2011

Scientists discovered that Bilayer Manganites (a compound of manganese, lanthanum, and strontium) have an unusually fragile, unstable magnetic state. This finding demonstrates the rich variety of spin couplings in these materials, which may be useful in engineering spintronic devices.

Bilayer Manganites are actually known for exhibiting "colossal magnetoresistance" - a drastic change in electrical resistance in response to a magnetic field - and the new research shows that they also have this new magnetic state.

Electron spin-splitting effect (Rashba effect) was demonstrated in a semiconductor (Bismuth selenide) that is far larger than has ever been seen before. This could lead the way towards room-temperature spintronic devices. The Rashba effect is the phenomenon of spin splitting with an applied electric field instead of a magnetic field.

The Rashba effect is crucial for spintronic devices: for example when designing spin transistors, electrons of a single spin are injected and then – under an applied electric field – have their spins rotated. Rashba effect in well-established semiconductors (silicon or gallium arsenide for example) is very small - and so electrons have to travel large distances before any spin rotation is noticeable. This requires very pure materials and very low temperatures.

Graphene can adsorb oxygen onto its surface (which changes graphene's electronic transport properties). This can be useful for Spintronics devices, but the adsorption is difficult to control. Researchers from the Tokyo Institute of Technology developed a way to control the adsorption of oxygen by applying an electric field to a Graphene-based field-effect transistor (FET).

via Graphene-Info

Researchers from Virginia Commonwealth University created an integrated circuit using spintronics and straintronics. The new IC design uses very little energy - in fact it could run merely by tapping the ambient energy from the environment.

The researchers say that while Spintronics promises very low power switching, when ramped up to usable processing speeds, much of that energy savings is lost because the energy is transferred to the magnet. The new design uses a special class of composite structure called multiferroics (a layer of piezoelectric material with intimate contact to a magnetostrictive nanomagnet). This generates strains in the piezoelectric layer when voltage (even a tiny voltage) is applied - which is then transferred to the magnetostrictive layer. This strain rotates the direction of magnetism, achieving the flip.

A team of researchers from Diamond, Exeter, Grenoble and Leeds have published a new paper describing interesting results from a new experiment - magnetic lensless imaging by Fourier transform holography using extended references. Characterization of magnetic states on the submicron scale could lead to rapid advances in understanding and utilizing the properties of new materials for spintronic devices.

The team reports clear images of magnetic domains in a Co/Pt multilayer thin film with perpendicular magnetic anisotropy. This technique can directly image magnetic configurations within an applied field and could help to advance magnetic logic and race track memory devices, which require an understanding the propagation and controlled pinning of magnetic domain walls along nanowires.

Scientists from The University of Nottingham, UK, developed a new self-assembly based method to create sulphur-terminated graphene nanoribbon within a single-walled carbon nanotube. They say that these ribbons have some interesting physical properties and they are suitable for applications in electronic and spintronic devices - more so than 'regular' graphene.

The team have demonstrated that carbon nanotubes can be used as nanoscale chemical reactors and chemical reactions involving carbon and sulphur atoms held within a nanotube lead to the formation of atomically thin strips of carbon, known as graphene nanoribbon, decorated with sulphur atoms around the edge.

Durham University spun-off a new company called Rhomap to develop manufacture-to-order scientific instrumentation for high precision magneto-transport measurement systems. Rhomap's instruments targets new materials and next generation semiconductors, photovoltaics, spintronics and ferromagnetic systems.

The new Ohmpoint Measurement System is a flexible research tool that offers a range of software selectable sample connection probe geometries in one system. The instrument allows users to measure resistance in two or four point geometry, sheet resistance and magneto-transport behavior, including Hall effect and magnetoresistance. The flexibility of the system also enables the user to easily select between individual measurements and batch scanning of multiple samples.

German researchers have found for the first time a regular lattice of magnetic skyrmions (cycloidal vortex spin structures of exceptional stability) – on a surface. This fascinating magnetic structure was discovered by spin-polarized scanning tunneling microscopy and imaged on the atomic scale.

The magnetic skyrmion lattice discovered in Hamburg occurs in an atomically thin film on a surface. The interplay of various magnetic interactions is the cause for the occurrence of this complex structure. While the canting of atomic spins with a certain rotational sense is caused by the antisymmetric Dzyaloshinskii-Moriya interaction, the skyrmions found here can only be induced by the so-called four-spin interaction with the participation of four magnetic atoms.